really basic iteration

Share icon

Hi everyone,

here is the thing. i want to write a simple macro that, let's say, differentiate waves that have the same root name. i e. wave0, wave1, wave 2, etc. so, instead of going
differentiate wave0
differentitate wave1
differentiate wave2
...etc

i want to do something like

variable n = 0
differentiate wave(n)
n+=1
etc

but i have have a problem with the basic syntax, and i am not able to find the right way to do it in the monstuous manual.

so, i woul really appreciate some feedback on this simple matter.
thanks in advance.

have a nice weekend

P 
// this function iterates through all waves of a given template basename
Function DoMyThingOnSetofWaves(basename)
     string basename
 
     // define variables and strings
     variable ic, nt
     string theList, theOne
     // get a (string)  list of all wave names that fit the template
     theList = WaveList(basename,";","")
     nt = ItemsInList(theList)
     // iterate through the list
     for(ic=0;ic<nt;ic+=1)
          // get the next name that fits the rule
          theOne = StringFromList(ic,theList)
          // convert the string name to a wave reference
          wave wwave = $theOne
          // do it to it
          DoMyThingOnOneWave(wwave)
     endfor
     return 0
end
 
// this function does something on only one wave
Function DoMyThingOnOneWave(ww)
     wave ww
 
     differentiate ww
     return 0
end


Once you do this, on the command line, you can try ...

make/n=100 sinx0=sin(x), sinx1=sin(1/x), sinx2=sin(x^2), sinx3=sin(x^3), sinx4=2*sin(x),cosx0=cos(x)
display sinx0,sinx1,sinx2,sinx3,sinx4,cosx0
domythingonsetofwaves("sinx*")


HTH

--
J. J. Weimer
Chemistry / Chemical & Materials Engineering, UAHuntsville

August 21, 2010 at 06:55 am - Permalink
[quote=jjweimer]
nt = numpnts(theList)
[/quote]

This line should be:

nt = itemsinlist(theList)

(I actually don't know, why the compiler throws no error.)

August 20, 2010 at 02:02 pm - Permalink
[quote=awirsing][quote=jjweimer]
nt = numpnts(theList)
[/quote]

This line should be:

nt = itemsinlist(theList)[/quote]

Fixed. Thank you.

[quote=awirsing](I actually don't know, why the compiler throws no error.)[/quote]

I wrote it here, not in Igor.

--
J. J. Weimer
Chemistry / Chemical & Materials Engineering, UAHuntsville

August 21, 2010 at 06:56 am - Permalink
[quote=jjweimer][quote=awirsing](I actually don't know, why the compiler throws no error.)[/quote]

I wrote it here, not in Igor.
[/quote]

But I pasted it into the procedure window and it compiled without error, although numpnts is supposed to work on waves (and not on strings).

August 21, 2010 at 07:50 am - Permalink
Hi guys,

I tried the function and it works just fine. Many thanks.
I have a small problem though. I need to preserve the original waves, meaning each derivative should be stored in a different wave. Now, if I try to duplicate the source waves before differentiation or store the derivative in a new wave I encounter again the same problem, meaning having to rename output waves in numerical order, such as wave0_DIF, wave1_DIF, wave3_DIF. Could you please give a suggestion to solve this little problem?
Thanks

P

August 23, 2010 at 04:20 am - Permalink
[quote=pjfd]I need to preserve the original waves, meaning each derivative should be stored in a different wave. Now, if I try to duplicate the source waves before differentiation or store the derivative in a new wave I encounter again the same problem, meaning having to rename output waves in numerical order, such as wave0_DIF, wave1_DIF, wave3_DIF. Could you please give a suggestion to solve this little problem?[/quote]

// this function iterates through all waves of a given template basename
Function DoMyThingOnSetofWaves(basename)
     string basename
 
     // define variables and strings
     variable ic, nt
     string theList, theOne,theSecond
     // get a (string)  list of all wave names that fit the template
     theList = WaveList(basename,";","")
     nt = ItemsInList(theList)
     // iterate through the list
     for(ic=0;ic<nt;ic+=1)
          // get the next name that fits the rule
          theOne = StringFromList(ic,theList)
          // create output wave name
          theSecond = "DIF_" + theOne
          // duplicate source wave
          duplicate/o $theOne $theSecond
          // convert the string name to a wave reference
          wave wwave = $theSecond
          // do it to it
          DoMyThingOnOneWave(wwave)
     endfor
     return 0
end


I prepended the 'DIF_' suffix, because otherwise you will end up with something like wave0_DIF_DIF if you call the function twice.

A.

August 23, 2010 at 12:38 pm - Permalink
thanks. that has all been useful and works fine.
final point: i would like to plot in one graph multiple waves, such as
wave0 vs wave1, wave 2 vs wave3, wave4 vs wave 5, ... and so on. is there a simple way to do it with a function? i have more than a thousand pairs, so i cannot go doing it by hand

P

August 26, 2010 at 12:42 am - Permalink
[quote=pjfd]thanks. that has all been useful and works fine.
final point: i would like to plot in one graph multiple waves, such as
wave0 vs wave1, wave 2 vs wave3, wave4 vs wave 5, ... and so on. is there a simple way to do it with a function? i have more than a thousand pairs, so i cannot go doing it by hand

P[/quote]

It can be done, but it strongly depends on how your wave are named.
Steps that may be involved are:
create a stringlist for the y waves and the x waves (see wavelist, sortlist, etc.)
iterate trough the lists and convert each item into an wave reference (see stringfromlist, wave, for-endfor, etc.)
and append them to the graph (see appendtograph)

Andreas

August 26, 2010 at 01:17 am - Permalink
[quote=awirsing][quote=pjfd]
wave0 vs wave1, wave 2 vs wave3, wave4 vs wave 5, ... and so on.[/quote]
It can be done, but it strongly depends on how your wave are named.[/quote]

With the short list above using only ten waves where they are plotted as odd versus even, you would be able to generate the x-wave and y-wave lists using a GrepList command of the type ...

string theList = WaveList("",";","")
string thexList = GrepList(theList,"wave[13579]")
string theyList = GrepList(theList,"wave[02468]")


Extending this code to work for sequences of waves beyond ten is left as an exercise for the reader :-)

ANSWER:

string thexList = GrepList(theList,"wave.*[13579]")


--
J. J. Weimer
Chemistry / Chemical & Materials Engineering, UAHuntsville

August 26, 2010 at 06:27 am - Permalink
[quote=pjfd]i would like to plot in one graph multiple waves, such as
wave0 vs wave1, wave 2 vs wave3, wave4 vs wave 5, ... and so on.[/quote]

Presuming your wave names are as quoted here, the recent development release of LinkDisplay will now allow you to do the following at the command line or in a procedure:

string/G theYGrep = "wave.*[02468]"
string/G theXGrep = "wave.*[13579]"
string/G theYWaveList = GrepList(WaveList("*",";",""),theYGrep)
LinkDisplay#LinkWithGREP(theYGrep,theXGrep)
display
LinkDisplay#LAppendtoGraph(theYWaveList)


The last two lines presume that you want to show all y-waves on one graph. If each y-wave is to be shown on its own graph, do instead ...

LinkDisplay#LDisplay(theYWaveList)


The help file for LinkDisplay explains briefly the command syntax.

--
J. J. Weimer
Chemistry / Chemical & Materials Engineering, UAHuntsville

August 26, 2010 at 12:35 pm - Permalink
pjfd, since you find yourself doing these sort of tasks often, you might want to create wave references inside a loop, like:

display
variable i=0
for (i=0; i<1000; i+=1) // string reference
    wave thisWave = $("baseName" + i)
    appendToGraph thisWave 
endfor
for (i=0; i<1000; i+=1) // string command
    sprintf cmd, "print waveMax(%s)", ("baseName" + num2str(i))
    Execute cmd
endfor


I'm not sure whether this is "recommended" but I find it useful when I don't want to use wave0 wave1 wave2 style names.

August 30, 2010 at 12:13 pm - Permalink